1. Field of the Invention
This invention relates to a nonmagnetic conductive material separating apparatus preferably adapted for separating a nonmagnetic conductive material represented by aluminum cans from a mixture material collected as waste.
2. Description of the Prior Art
A mixture material collected as waste, generally speaking, is supplied into a magnetic sorter, so that a magnetic material represented by iron pieces is removed from the mixture material. The mixture material from which the magnetic material has been removed by the magnetic sorter is largely classified into a nonmagnetic nonconductive material represented by wood pieces and waste paper, and a nonmagnetic conductive material represented by aluminum cans. To the effect that the former is separated from the latter, the mixture material is supplied into the nonmagnetic conductive material separating apparatus.
The inventor of the present invention has proposed a separating apparatus in U.S. Application Ser. No. 59,648, now U.S. Pat. No. 4,230,560. The separating apparatus includes a drum rotating in one direction about the longitudinal central axis inclined with respect to the horizontal plane and having an equal inner diameter throughout the length thereof; a chute through which a mixture material to be separated is thrown into the drum from the upper opening thereof; and a means for generating a shifting magnetic field for exerting an electromagnetic force opposite to a rotating direction of the drum on the conductive material contained within the mixture material moving toward the lower opening of the drum.
In the separating apparatus, the mixture material thrown from the upper opening of the drum through the chute into the drum is forced upward along the inner peripheral wall of the drum in the direction of rotation of the drum due to friction relative to the inner peripheral surface of the rotating drum, and then slid down therefrom due to its own weight. The mixture material is moved up and down in the drum in a meandering fashion in the state of being deviated toward the direction of rotation along the bottom wall of the drum toward the lower opening. During the above-described movement, the mixture material passes a magnetic field zone produced by the magnetic field generating means. In the magnetic field zone, the conductive material receives the electromagnetic action, so as to be separated from the nonconductive material. In order to increase the separation efficiency by the action of the electromagnetic force, it is desirable that the conductive material and the nonconductive material which are interwined with each other be loosened before the mixture material arrives at the magnetic field zone.
In the prior art separating apparatus described above, the conductive material twined about or held on the nonconductive material, such as waste paper has been partially loosened, and hence, both are likely to move through the drum integrally, resulting in poor separation efficiency.